Pressure sensitivity pen left click shortcut

Whenever I use my Wacom tablet in Gimp, the default mouse is still visible, unlike in Krita. I have a keyboard shortcut on my pen set to left click, so I can draw with the pen without touching the tablet surface (I use this for erasing/coloring.) This works well with Krita, but when I use Gimp, it treats the left click as a right click. Is there a way to fix this?